Ultimate interior insulation for sound and heat?

[84 chevy guy id]

I am building an 86 chevy crew cab, 12 valve cummins/4l80e/241 with dana 60's running 3.54 gears. I want it to be as quiet and cool as possible inside. Whats the best stuff to put on the outside as well as the inside?

TIA,
Mike

[bd]

I used Dynamat Extreme for the base, overlain by a 1/2" thick aluminized rag fiber blanket.  Used that combination on the floor, the firewall and the cab rear wall.  Used Dynamat Extreme on the roof above the headliner, on the doors, and behind the dash.  Truck is Cadillac quiet and well insulated from heat/cold.

[78 Chevyrado]

I used elemental designs on my truck

http://www.edesignaudio.com/product_info.php?cPath=1_24&products_id=51

I bought it because it was cheaper to use than the big brands, I put it on double thick in some places and still came out cheaper.  I like the stuff.  does what it's supposed to, and its still stuck real good everywhere i put it 3 years later.  didnt need a heat gun either, I just did it on an 80 degree or so day and it went right in and stuck.

I did inside the doors, up the b pillar, the floor and I dont get any noise except the AC and the vent windows.  also with my stereo all the way up you can't hear it 8 ft from the truck.

I'd buy more of it.  and they have better stuff now than they did then.

[firefighter]

For a sound insulator I used an inexpensive roofing product called Peel & Seal purchased from Lowes.
Here is a link:
http://www.lowes.com/pd_154017-81326-PS625_0__?productId=1018733&Ntt=peel+seal&pl=1&currentURL=%2Fpl__0__s%3FNtt%3Dpeel%2Bseal&facetInfo=#BVRRWidgetID
Read the reviews on it.

I installed it on the inside of my firewall, on the floor, and the insides of the outer door skins. It took 3 rolls.
Now I'm not pushing this stuff because quite honestly my truck isn't even done yet and I haven't had it on the road, but I can tell you that when I shut my cab doors that they shut with a dull thud. There is no hollow metal clanking type sound that I used to remember. I'm a tight wad and I had read about this stuff somewhere on this forum and was impressed by it when I started putting it on.

I just wanted to give you another option to look at.

To insulate from heat, I believe you may need some type of specific insulation material.

[ehjorten]

I would avoid using asphalt-based material on the inside of your ride!  In the Summer months it is going to melt off and give a horrible tar stink to the inside of your vehicle!!  Also, when they become un-glued due to the melt-off they are basically useless.  Use a Butyl rubber based product instead.

I my opinion the Dynamat stuff is way over-priced.  Other solutions are out there that are much more cost effective.

[Edahall]

I am building an 86 chevy crew cab, 12 valve cummins/4l80e/241 with dana 60's running 3.54 gears. I want it to be as quiet and cool as possible inside. Whats the best stuff to put on the outside as well as the inside?

TIA,
Mike

What year 12 valve Cummins are you using?  FYI, the older VE pump 88-93 Cummins are much quieter than the P-pump version. 

[Skunksmash]

According to what I've found, as long as its not Asphalt based, you're good. Make sure its buytl based. Butly is really just some kind of rubber but very sticky. Its what all the big brands use, like dnyamat and such. As per the recommendations around here, I'll probably be going with cascade from now on. They seem to have the claim that you don't need all this excess stuff, like all the other brands want to sell you. It just adds weight. You're only going to get so much sound deadening so they say there is no point going overboad and they sell exactly how much it takes to get the maximum possible effect. The others try to sell all this extra that doesn't really even help.

But I will be buying a couple different hood mats that do a couple different things, and spraying some kind of deadening undercoating under the truck, eventually. So that's more stuff to consider.

[ehjorten]

If you are trying to deaden sound and not insulating a particular area then, yes you do not need to completely cover a panel.  There are basically two types of sound transmission, air-borne and structure-borne.  For the air-borne noise it is like a speaker and the panel acts like the cone.  If you have large flat areas of sheetmetal they are going to transmit noise the most and they will be lower frequency noises.  Areas where there is a lot of forming going on with ribs and other features formed into the sheetmetal are going to be much stiffer and will not transmit much noise.  Noise that is transmitted will be high frequency noise, but it will not be very powerful.  Low frequency noise is also hard to cancel without having VERY thick insulation, so adding 1/4" butyl rubber insulation isn't going to cancel it out anyways!  Structure-borne noise is noise that is transmitted through the structure of the vehicle.  For example...engine vibration being transmitted through the frame and into the cabin of the vehicle.  In order to cancel this type of noise you need a stiff-soft-stiff configuration of materials.  So something like Steel-rubber-steel.  The soft material needs to be something like 10 times softer than the stiffer mating material to be really effective.  This is the reason why we have rubber isolators and the like for engine mounts and cab mounts.

Finally...if you have any holes in your firewall or backwall or whatever...Plug them up!!!  Even small holes can transmit a large amount of noise.

[84 chevy guy id]

Its a 94 with a "p" pump. Thanks for the tips guys, gives me some good ideas

[whargis]

This is a topic that you're going to find 1001 different opinions...  I too am redoing my interior and I've been doing a ton of research on sound deadening products.  The best place to look is the car audio forms - these guys really know what they're talking about as sound deadening also improves speaker sound.  Read this - this guys did an independent test on some of the larger names out there - http://www.dctra.org/files/1974_TR6_Carpet_Install/Sound_Deadener_Showdown.pdf.  This guy now sells his own product - http://www.sounddeadenershowdown.com/cgi-bin/index.cgi.

From what I found - you need to add mass to deaden vibration and then you need something that will block/absorb high and low frequencies (to get that nice, new, expensive, car sound).

I emailed the sound deadener showdown (SDS) guy and sent him my measurements of my 86 single cab - he came back with a very lengthy email about what I should use and how much and at what cost.  It was a little pricey more than I was willing to spend but at the end of the day is was some awesome info.  Price was about $600 to cover anything and everything - this was still cheaper than some of the more known products like second skin and  Dynamat.  Raamat is another product that has some great reviews and a respectable price, however I sent them two emails but never heard back (I don't do business with guys like this - no matter how great and cheap the product is).  Raamat essentially have the same product as SDS - add tiles to dampen vibration and then add some sort of closed cell foam product to block sound.  Elemental Designs (Edead) was another company I contacted - they were by far the cheapest - they sell a few products that can give you the results you want:  Paint/spray-on and stick-on.  The paint is a good deal - but I was concerned about not being able to remove the stuff in case I needed to repair something.  They guys were very fast to respond and very friendly to work with but they have a bad rap from a few years ago about some bad customer service - not anything I experienced.   

I'm not sure how these items performed for insulation - which was something I was interested in as well.  I found a product called AcoustiSHIELD - It comes in pre-cut packets that fits the vehicle you're looking for.  I couldn't find many reviews on this stuff except from some Mustange people but everyone seems to like it.  It provides vibration deadeners (dynamat) then sound absorption and heat insulation. 

I ultimately decided to buy the AcoustiSHIELD as Dynamat is well known and the panels will not melt (like most asphalt based panels) and they stick very well.  It also has insulation - which the other products didn't have.  Edead was my second choice - they were very competitively priced and like 78 Chevyrado commented - they have some new and improved products. 

My AccoustiSHIELD arrived on Monday and I'm hoping to install everything by the end of the weekend (I had to repair rust and am waiting on the weather to warm up so I can paint - which should be tomorrow).  It was a little more than what I wanted to spend.  It was about $150 more than what edead would have run but still a few hundred less than SDS. 

On a side note - I would be a little caution about using anything asphalt based - like Peal and Seal.  I think it will depend on where you live.  I have a friend who lives in Dallas and he installed the Peal & Seal in Feb and by the end of the summer it had all melted and moved around - it was a huge mess to clean up.  He said it worked great for a few months until the weather got hot then it was like he didn't put down anything at all - and it smelled like a fresh paved road.  I'm sure it works fine in the cooler states so that's something to consider if you live up north. 

[Edahall]

Whargis,
Very good post.  Please reply back when you get finished at let us know how well the AccoustiSHIELD did to make your cab quiet.
_______

Here's another idea I have thought about that would be very cheap.  Buy some cheap latex paint and mix it with sand.  Apply a very thick coating of the paint/sand mixture to areas that need quietening.

Once that's done, apply carpet underlay over the whole flooring.

[whargis]

Edahall,

You bet - I've been taking pictures of the process as my family is suprissed I'm taking on this type of project (considering I have zero experience).  I'm concerend as I may not notice a huge difference until I replace all the rubber on my windows and doors - lots of wind noise.  However, I should notice a difference in road, engin, and exhause noise and will post my findings.  The doors/windows will be my next step. 

[ehjorten]

To add a bit more to the discussion...some of the best acoustic insulation that is available to the general public is a 3M Thinsulate material.  It is kind of hard to find, but a lot of marine shops will have it.  You can get it in rolls and it is usually 1" or 2" thick.  YES...1" or 2" thick!  That limits where it can be used, but it is very effective and much more light-weight than some of the other stuff.  The problem with noise is that the lower frequency stuff requires the thickness be at least 1/4 of the sound wavelength.  A 100 Hz (speed of sound in air is about 1,115 feet per second) has a wavelength of 1,115/100 = 11.15 feet.  Divide that by 4 and you get 2.79 feet!!!  So it is not practical to apply sound absorption for low frequencies.  2" thick insulation can absorb sound above ~1,670 Hz.

Some important things to consider for two different types of noise...

Air-borne noise: Barriers on the floor, firewall and side walls (that is where most of the noise comes from); no cracks, holes or gaps!; air-tight seals for all pass-throughs; and sound absorption inside the cab (not practical for low frequencies).

Structure-borne noise: About the only thing that you have available to you as an end-user of an engineered vehicle is the application of damping materials on the structure (i.e. the butyl rubber products like Dynamat) and again sound absorption products like the thinsulate material i mentioned.  Beyond that...don't use Polyurethane cab mounts or polyurethane engine mounts if you want vibration and structure-borne noise cancellation.